The present invention relates to a spigot-and-socket joint for connecting two pipes, pipe fittings or the like, comprising a socket end which is assigned to one pipe and into which a spigot end of the other pipe, which has a support strip, can be inserted and which has a radially inward-protruding edge with at least one ring segment-shaped recess, and a locking device for locking the spigot end in the socket end, in that the support strip rests against the locking device and said locking device rests against the edge, the locking device comprising at least two ring segment-shaped locking elements.
Spigot-and-socket joints of the aforementioned type are known for example from document DE 199 187 17 C1. They serve to produce a rubber-sealed connection between two pipes which are usually under pressure. For tensile securing, these known spigot-and-socket joints have locking devices which prevent the spigot end of one pipe from being extracted from the socket end of the other pipe.
A locking device of this type comprises two locking elements or bars which are made of metal and each have at one end a projection (stop elements) serving as a stop.
To attain a spigot-and-socket joint, the spigot end is first inserted into the socket end until it strikes against the socket base. Subsequently, one bar is inserted into the socket recess and displaced in the clockwise direction until the projection strikes against the edge of the recess. The bar rests in this position in the radial direction against the spigot end of the pipe and in the axial direction, on the one hand, against the support strip and, on the other hand, against the inside of the edge of the socket end.
Subsequently, the second bar is also inserted into the recess of the socket end and displaced in the anticlockwise direction until the projection strikes against an edge of the recess. This bar also rests, both in the radial and in the axial direction, in the same manner as the first bar.
Although this spigot-and-socket joint has proven highly successful in practice, there is still the need to improve both the handling and the operation, and also to reduce the manufacturing costs.
Document DE 33 36 855 A1 also discloses a locked, plug-in connection for pipes, in particular socket pipes. In the case of this solution there is provided in the socket, before a ring seal viewed from the socket end, an annular recess, of which the portion that is directed toward the socket end is delimited by a conical surface and in which is arranged at least one locking part which rests radially on the conical surface and with a cylindrical support surface on a spigot end introduced into the socket and also axially on the conical surface and against a retaining collar surrounding the spigot end. The locking element or elements is/are inserted via a single opening and have to be oriented, wherein in practice the locking elements can then be secured in the oriented position by means of a tightening strap. Depending on the nominal width, a large number of locking elements can be inserted, although this system is in practice available only from a nominal width of DN 700.
Overall, the handling of the locking elements, in particular the inserting and orienting thereof, is complex.